Primary structure of cyanogen bromide fragments of sei whale (Balaenoptera borealis) pituitary somatotropin
Pankov, I.A.; Bulatov, A.A.; Osirova, T.A.; Keda, I.M.; Sinntsina, A.L.
Biokhimiia 41(11): 2047-2055
1976
ISSN/ISBN: 0320-9725 PMID: 1022273 Document Number: 103606
5 fragments are isolated after the degradation of somatotropin from sei whale pituitary glands with cyanogen bromide: N-terminal 4-segmented; C-terminal 12-segmented with the internal disulfide bond; middle 25- and 30-segmented and a high molecular weight fragment following N-terminal tetrapeptide and bound with disulfide bond to 30-segmented fragment. Complete amino acid sequence of three shortest cyanogen bromide fragments is deciphered and N- and C-terminal sequence is investigated in two large fragments after their uncoupling under performic acid oxidation. Amino acid sequence is deciphered of a peptide obtained after trypsine hydrolysis of 30-segmented cyanogen bromide fragment. Comparison of amino acid sequence of whale somatotropin fragments with that of sheep, beef and human somatotropin has revealed that 57 out of 61 identified amino acid residues of whale somatotropin repeat amino acid residues in similar regions of beef somatotropin, 56--of sheep and only 42--of human somatotropins. Besdies, 4 of 5 revealed amino acid substitutions in whale hormone, as compared with sheep somatotropin, are amino acids which are present at the same positions in human hormone.